This invention pertains to agricultural forage harvesters and more particularly to an improved recutting means in the recutting section of the harvester.
Forage harvesters are used by many farmers for the cutting and loading of chopped forage material. This material may be hay crops or the plants of many grain crops either before or after the grain is harvested. The harvester is built to include at least three operations in most instances. First, the crop is either picked up from a windrow into which it has been laid by other machinery, or in some cases it may be directly cut from the ground. Second, it passes to a recutter where it is chopped into small bits. Third, it is blown through a chute into a wagon or other container for transportation or storage.
In the ordinary machine, the recutter section includes a rotating cutter unit and a screen through which the material passes on its way to the blower. The cutter is ordinarily a rapidly moving series of knives which engage the material and chop it into bits as it enters the cutter. However, much of the material is not cut by the chopping action and so it is necessary that an edge be provided for shearing that material between it and the rotating blades. The screen is a convenient means of providing a blade against which the rotating blades may shear, and several types of screens have been proposed.
Previous screens have been principally curved members having punched slots or holes. These openings provide a passage for the material to go through and also provide cutting edges. However, in no case is there any provision for sharpening the edges. As they become dull, there is more and more power required to drive the cutter and it becomes less and less efficient.
By my invention I provide for a recutter which effectively allows passage of the material while also providing a cutting edge, or a plurality thereof which can be resharpened to provide for a continued high efficiency cutter.